scholarly journals Extreme Hydro/chemical Phenomena in a River System during the Snowmelt Period

2013 ◽  
pp. 20-31
Author(s):  
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
River System ◽  
High Water ◽  
Snowmelt Period ◽  
River Bed ◽  
Extreme Behavior ◽  
Successive Period ◽  
Permanganate Oxidability ◽  
Moskva River

Development of extreme hydro/chemical phenomena during the snowmelt periods in the Moskva River (Rublyovo) and their interrelations with the water flow in the river have been investigated. The analysis was based on the rows of water quality daily average values including turbidity, color, permanganate oxidability, alkalinity, pH, chlorides, ammonia ion, iron, as well as the data on the river water flow. A two-month rated period March 15 – May 15 has been identified out of the data rows over 15 years of observations (1997–2011). It has covered the high water peak, preceding waves of thaw and successive period of relaxation. Special features of the indicators extreme behavior during the said period have been described. Variability of indicators during the snowmelt period was illustrated by the 1998 and 1999 data when washing of the river bed was carried out. During these measures performing links between water quality indicators and water consumption were the most obvious. Определен суммарный сток ингредиентов за половодье в зависимости от стока воды. It has been demonstrated that this dependency obeys the linear law.

scholarly journals Toward the understanding of saline water intrusion and nutrient flushing in Lake Nokoué

2021 ◽  
Author(s):  
Metogbe Djihouessi ◽  
Rita Houngue ◽  
Firmin Adandedji ◽  
Luc Sintondji
Keyword(s):  
Water Quality ◽  
Atlantic Ocean ◽  
Water Level ◽  
Water Flow ◽  
River Flow ◽  
Saline Water ◽  
High Water ◽  
The North ◽  
High Water Period ◽  
Mike 21

To understand the salinity dynamic at the outlet of Lake Nokoué and to simulate the nutrient flushing from this lake into the Atlantic Ocean, a 2D hydrodynamic model was designed with Mike 21. The choice of the Mike 21 was motivated by the long practice that decision-makers in Benin have with this software. The Hydrodynamics (HD) module simulated water level variations and flows in response, while the ECO-Lab module has been used for water quality modelling. The data used covered the hydrological period of 2013. The results from the HD simulation indicated that for a flow of 725 m3/s at Bonou on the Ouémé River, a tributary of Lake Nokoué. 70% of the land in the delta of Ouémé, between the Ouémé River and the So River (also a tributary of Lake Nokoué), are flooded against 90% for a river flow of 1100 m3/s. The water level in the delta showed a water increase of 0.6 m, in seven days, for a water flow of 725 m3/s at Bonou and a water increase of 1.3 m, in seven days, for a water flow of 1100 m3/s at Bonou. Water quality simulations indicated that the seawater intrusion from the Atlantic Ocean into Lake Nokoué occurred from the bottom to the surface towards the surface of the lake. During flooding, despite the large inflow of fresh water, more than 60% of the water at the bottom of the lake had concentrations greater than 8. Simulation of the dispersion of nutrient point source pollution indicated that there was an accumulation of pollution at the bottom of the lake during low water periods. This accumulation increases in amplitude as one moves away from the Atlantic Ocean towards the north of the lake. In this period tidal flushing evacuated about 20% of the pollution ejected. In the high water period, about 70% of the pollution ejected in the lake was automatically flushed out in the lake the Atlantic Ocean.

scholarly journals The Timing of the Onset of Lows of the Summer-Autumn Low Water in the Basin of Upper Don

2019 ◽  
Author(s):  
Keyword(s):  
Water Content ◽  
Water Flow ◽  
River System ◽  
High Water ◽  
Left Bank ◽  
Absolute Minimum ◽  
Quality Of Water ◽  
Current Century ◽  
The Absolute ◽  
The Right

Considered the timing of the onset (with rounding up to a month) lows of the summer-autumn low water period in the basin of the Upper Don for the periods: from the beginning of the observations in the posts, before 1970, 1971-2000, 2001-2017. Three zones have been identified that differ in generation time of the absolute lows of water flow: the Don itself and the right-bank tributaries of the Don; the left-bank tributaries of the Don; a basin Hoper. It is established that in the current century the absolute minimums of water flow are formed in the selected zones in July – August, August-September, mainly in September, respectively, which is about a month earlier than the dates observed before 1970. The main shifts in the onset dates of the investigated characteristic occurred in 1971-2000, fixed in the current century. In the Hoper basin, there is greater consistency in the onset of absolute lows of water flow than in the river system of the Upper Don. Despite the increase in the duration of high water and summer-autumn low water, as well as the tendency of increasing water content in the period of low runoff, there is a movement of formation dates of low extrema of water content to the beginning of summer-autumn low water. The identified nature of the formation of absolute minimum is apparently the result of intra-annual redistribution of the flow and a response to the positive dynamics of air temperature, which directly or indirectly infruences the hydrological processes in the river catchment area. Earlier summer depletion of rivers can contribute to increased risks of water use during the summer-autumn low-water period, adversely affect the agricultural sectors focused on the use of water for agricultural water supply, significantly change the quality of water in water bodies and create environmental tensions in the basin.

scholarly journals Water Quality Changes during High Water Flow in Small Rivers : A Case Study in Ono River, Matsuyama

2002 ◽  
Vol 7 (2) ◽  
pp. 31-38
Author(s):  
Junsheng Gao ◽  
Tadao Fukushima ◽  
Masayuki Fujihara ◽  
Toshiko Kakihara ◽  
Takashi Watanabe
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
High Water ◽  
Small Rivers ◽  
Quality Changes

scholarly journals Mathematical modeling and forecasting the dynamics of a segment of the river bed of Seversky Donets river

2019 ◽  
Keyword(s):  
Water Quality ◽  
Bottom Sediments ◽  
Dynamic Pressure ◽  
Geometric Model ◽  
Three Dimensional ◽  
Viscous Friction ◽  
River System ◽  
Positive Feedbacks ◽  
Flow Parameters ◽  
River Bed

The flow in the section of the Seversky Donets river in Kharkiv region is studied based on long-term measurements of the channel profile in a 10 cm increments. The geometry of the studied channel section on the Earth's surface has been determined by hydrological maps, and the cross-section profiles have been reconstructed by splines from the measurement results. The analysis of the results has revealed the profile variability in accordance with the change in the bottom sediments and the current year rainfall. A mathematical model describing the flow parameters in dependence on the slope and profile of the river channel has been developed. The model allows calculating flow velocities, dynamic pressure and viscous friction, predicting the evolution of coastal channel lines, the presence of stagnant zones with slow circulation, and predicting the dynamics of bottom drifts and channel overgrowing. Based on the three-dimensional flow of water in the channel with given geometry, numerical calculations by the finite element method are carried out. The flow rates are calculated and the presence of separated stagnant zones with slow circulation in which the channel overgrowth and water quality deterioration could be amplified is shown. Calculations of dynamic pressure and viscous friction shows the presence of areas with increased pressure which, in time, can ruin the riverbanks, contribute to the formation of bottom sediments, and increase the area of ​​stagnant zones with slow circulation. Since there is a system of positive feedbacks in the river ecosystem, the resulting deterioration in circulation and water quality cannot be stopped naturally and require special engineering and hydrogeological measures. The developed model allows planning various specific measures to prevent river erosion and overgrowth, to improve circulation and water quality by introducing the changes into the original geometric model as well as quantifying the changes caused by hydrodynamic factors that affect the evolution of the river system.

Radon removal by aeration: observations on testing, installation and maintenance of domestic treatment units

2009 ◽  
Vol 9 (4) ◽  
pp. 469-475
Author(s):  
T. Turtiainen
Keyword(s):  
Water Quality ◽  
Water Flow ◽  
Removal Efficiency ◽  
Flow Rate ◽  
Test Protocol ◽  
Household Water ◽  
Medium Flow ◽  
Removal Efficiencies ◽  
Frequent Sampling

Radon is one of the contaminants that sometimes impair the water quality of wells, especially those drilled in bedrock. Domestic radon removal units based on aeration have been commercially available for more than ten years. In order to determine how effectively these units remove radon a new test protocol applying frequent sampling while letting 100 litres of water flow, was developed. This way, removal efficiencies can be more accurately calculated and possible malfunctions detected. Seven models of domestic aerators designed for removing radon from household water were tested. The aerators were based on diffused bubble aeration, spray aeration or jet aeration. The average removal efficiencies for 100 litres with a medium flow rate were 86–100% except for a unit that circulated the aerated water back to the well that had removal efficiency of 80% at the maximum. By conducting a questionnaire study usual problems related to the aeration units were localized and recommendations on maintenance and installation are given accordingly.

Nutrient Input and Trophic Status of the “Neue Donau”, a High-Water Control System along the River Danube in Vienna, Austria

1990 ◽  
Vol 22 (5) ◽  
pp. 137-144 ◽  
Author(s):  
M. T. Dokulil ◽  
G. A. Janauer
Keyword(s):  
Water Quality ◽  
Control System ◽  
Trophic Status ◽  
High Water ◽  
Nutrient Concentrations ◽  
Nutrient Input ◽  
Water Control ◽  
Trophic Conditions ◽  
River Danube ◽  
High Nutrient

The system “Neue Donau” functions as a control system for high waters of the river Danube and is an important recreational area for many people. Water quality and trophic status of the water body is thereforeof prime importance. The high nutrient concentrations of the river Danube (P-tot 238±41µg/l, N-tot 2.53±0.78 mg/l) reach the system via groundwater seepage. Present conditions in the basin of Neue Donau are,as a result of this nutrient in-flux,eutrophic to hypertrophic. Average values during the summer period have declined from 366 µg/l total phosphorus to 78 µg/l, and from 86 µg/l chlorophyll-a tol7µg/l between the years 1985 and 1988. However, a dam which is planned in the river at Vienna will permanently raise the water level of the river thus increasing the the groundwater flow in the direction to the Neue Donau and therefore the nutrient input which will enhance trophic conditions in the impoundment. Since macrophytes play an important role in one part of the system macrophyte management together with measures along the river are some of the suggested strategies to keep the system Neue Donau at acceptable trophic conditions and good water quality.

scholarly journals Electron generation in water induced by magnetic effect and its impact on dissolved oxygen concentration

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Augustine Chung Wei Yap ◽  
Hwang Sheng Lee ◽  
Joo Ling Loo ◽  
Nuruol Syuhadaa Mohd
Keyword(s):  
Water Quality ◽  
Hydrogen Bonding ◽  
Dissolved Oxygen ◽  
Electron Density ◽  
Water Flow ◽  
Magnetic Effect ◽  
Water Quality Control ◽  
Electron Generation ◽  
Magnetic Effects ◽  
Do Concentration

AbstractpH, oxidation-reduction potential (ORP) and dissolved oxygen (DO) concentration are important parameters in water quality surveillance and treatment. The changes of these parameters are associated with electron density in water. Several techniques including electrolysis and catalysis which require redox reactions and electron exchange are employed to improve these parameters. In recent years, studies reported that magnetic effects can impart considerable changes on the pH, ORP and DO concentration of water. However, the correlation between electron density and magnetic effects on these parameters has yet to be disclosed despite the fact that increased electron density in water could improve water’s reductive properties, heat capacity and hydrogen bonding characteristics. In this study, the magnetic effects on pH, ORP and DO concentration were investigated using different magnets arrangements and water flow rates based on reversed electric motor principle. Results showed that the improvement of pH, ORP and DO concentration from 5.40–5.42 to 5.58–5.62 (+ 3.5%), 392 to 365 mV (− 6.9%), and 7.30 to 7.71 mg L− 1 (+ 5.6%), respectively were achieved using combined variables of non-reversed polarity magnet arrangement (1000–1500 G magnetic strength) and water flow rate of 0.1–0.5 mL s− 1. Such decrement in ORP value also corresponded to 8.0 × 1013 number of electron generation in water. Furthermore, Raman analysis revealed that magnetic effect could strengthen the intermolecular hydrogen bonding of water molecules and favor formation of smaller water clusters. The findings of this study could contribute to potential applications in aquaculture, water quality control and treatment of cancer attributed to free radical induced-oxidative stress.

scholarly journals Groundwater physico-chemical properties and water quality changes in shallow aquifers in arid saline wetlands, Ouargla, Algeria

2021 ◽  
Vol 11 (5) ◽  
Author(s):  
Fethi Medjani ◽  
Mohamed Djidel ◽  
Sofiane Labar ◽  
Louiza Bouchagoura ◽  
Chouaib Rezzag Bara
Keyword(s):  
Water Quality ◽  
Chemical Properties ◽  
High Water ◽  
Quality Changes ◽  
Shallow Aquifers ◽  
Shallow Water Table ◽  
Chemical Mechanisms ◽  
Desert Region ◽  
Physico Chemical ◽  
Hypersaline Water

AbstractShallow aquifers are vulnerable to natural geogenic processes as well as anthropogenic influences, and this is especially apparent in desert regions. Within arid and hyperarid climates, evaporation is a controlling hydrologic process leads to an important increase in the concentration of dissolved minerals of both surface water and groundwater. In groundwater, this increase is not only dependent on shallow water table depth, but also on the hydraulic properties of sediments present within the unsaturated zone of the aquifer itself. The main objective of this research is to investigate possible mechanisms that might influence water quality changes under seasonal conditions in shallow aquifers situated within the Saharan desert region of Algeria. In this work, we focus on observed changes in hydrogeochemical characteristics, and the possible responsible processes. Under arid conditions, high water mineralization results in hypersaline water or brine solution formation within shallow aquifers. Due to active physico-chemical mechanisms such as Na+/Ca2+ ion exchange, the successive precipitation of calcite, gypsum, mirabilite or blœdite and halite is induced. Biological processes were also observed as prevalent; evidenced by large measured variations in CO2 load concentrations. These processes contributed to an inverse relationship between CO2 and O2 concentrations within the shallow aquifers studied.

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